Optical reproducing method for optical medium with aligned prepit portion

摘要

An optical reproducing method using an optical medium having an aligned prepit portion straddled on a plurality of tracks in a radius direction. The prepit portion includes a first and second prepit portion divided in a track direction with a gap therebetween and with a synchronous information prepit of the respective first and second prepit portion being arranged on a boundary of the respective tracks. The synchronous information prepit and the first and second prepit portion is arranged at every two-track pitch in the radius direction and at opposite boundaries of the same track. An optical spot is irradiated on the optical medium, a reflected beam is detected from the optical medium, and information on the optical medium is reproduced by using a signal obtained by the reflected beam.